描述了C 2对称的手性O,N,N,O-四齿2,2-联吡啶二醇二醇丙烷配体的合成。Mukaiyama–Michael反应被用作合成2,2-联吡啶丙烷9的重要反应。在合成的配体中,配体11在二乙基锌和各种醛类化合物中均表现出出色的手性诱导(至多97%ee)。对于本催化体系,不需要在二乙基锌加成反应中使用额外的路易斯酸,例如Ti(O i Pr)4。
Chiral bis(amino alcohol)oxalamides as ligands for asymmetric catalysis. Ti(IV) catalyzed enantioselective addition of diethylzinc to aldehydes
作者:Gonzalo Blay、Isabel Fernández、Alícia Marco-Aleixandre、José R. Pedro
DOI:10.1016/j.tetasy.2005.01.039
日期:2005.3
Several chiral bis(aminoalcohol)oxalamides with C2-symmetry have been prepared and used as ligands for the enantioselectiveaddition of diethylzinc to aromatic and aliphatic aldehydes. The reaction proceeds in the presence of titanium isopropoxide to give the corresponding (S)-alcohols with ee up to 78%. In the absence of Ti(IV), the alcohols with the opposite configuration are obtained.
Synthesis of camphorsulfonamide-based quinoline ligands and their N-oxides: first use in the enantioselective addition of organozinc reagents to aldehydes
作者:Ricardo Martínez、Luca Zoli、Pier Giorgio Cozzi、Diego J. Ramón、Miguel Yus
DOI:10.1016/j.tetasy.2008.10.020
日期:2008.11
The preparation of several camphorsulfonamide-based quinoline derivatives and their N-oxides was accomplished via an indirectFriedländersynthesis using aminobenzylic alcohols and RuCl2(DMSO)4 as a catalyst. These ligands were tested in the enantioselective addition of dialkylzinc reagents to aldehydes, with enantiomeric excesses up to 96%. A similar protocol using triphenylborane and diethylzinc
an understanding of how chiral amplification is possible, in particular based on non‐lineareffects. Interestingly, it has been proposed a quarter century ago that chiral catalysts, when not enantiopure might even be more enantioselective than their enantiopure counterparts. We show here that such hyperpositive non‐linear effect in asymmetric catalysis is indeed possible. An in‐depth study into the underlying
Linear β-amino alcohol catalyst anchored on functionalized magnetite nanoparticles for enantioselective addition of dialkylzinc to aromatic aldehydes
作者:Carla Sappino、Ludovica Primitivo、Martina De Angelis、Francesco Righi、Federica Di Pietro、Marika Iannoni、Luciano Pilloni、Stefano Vecchio Ciprioti、Lorenza Suber、Alessandra Ricelli、Giuliana Righi
DOI:10.1039/d0ra04554c
日期:——
A linear β-amino alcohol ligand, previously found to be a very efficientcatalyst for enantioselective addition of dialkylzinc to aromatic aldehydes, has been anchored on differently functionalized superparamagnetic core–shell magnetite–silica nanoparticles (1a and 1b). Its catalytic activity in the addition of dialkylzinc to aldehydes has been evaluated, leading to promising results, especially in
L-Alanine-derived Chiral Ligands for Asymmetric Addition of Diethylzinc to Aldehydes
作者:Seock-Yong Kang、Jin-Ho Baek、Kyoung-Hee Kang、Jeong-Ae Lee、Yong-Sun Park
DOI:10.5012/bkcs.2012.33.9.3125
日期:2012.9.20
of efficient chiralligands for catalytic asymmetric addition of dialkylzinc. Among the various types of chiralligands explored several β-aminoalcohols have proven to be especially efficient ligands for the additions. However, the development of stable and easily accessible β-aminoalcoholligands is still desirable for practical applications. It is convenient that β-aminoalcohols can be prepared